This application claims the benefit of Korean Patent Application Nos. 2001-70522, filed Nov. 13, 2001, and 2002-54540, filed Sep. 10, 2002, in the Korean Intellectual Property Office, the disclosures of which are incorporated herein by reference.
1. Field of the Invention
The present invention relates to a maintenance apparatus of an inkjet printer having ink ejection nozzles, a capping member, and a wiping member, and more particularly to, a maintenance apparatus of an inkjet printer performing a stable maintenance operation as well as being minimized in size and a method thereof.
2. Description of the Related Art
Generally, an inkjet printer includes a paper feeder supplying paper one by one, a paper transporter transporting the paper supplied from the paper feeder one line at a time, a printing part printing data on the paper transported by the paper transporter, a paper-discharging part discharging the paper printed by the printing part, and a maintenance apparatus cleaning a surface of an ink ejection nozzle of at least one printing head, storing ink spat in a cleaning operation, and closing up the surface of the ink ejection nozzle when the printing head is not used.
Among these components of the inkjet printer, the maintenance apparatus maintains and preserves the ink ejection nozzle of the printing head in a normal state and is an apparatus essential to ensure the printing head to perform a good printing function.
The maintenance apparatus generally has a structure capping and wiping the surface of the ink ejection nozzle by using a cap and a wiper that are mounted on a moving member. The moving member disposed to be moved along tilted guide slots is ascended and descended by a moving force of a carriage in which the printing head is mounted.
Referring to FIG. 1, there is illustrated an example of the inkjet printer in which a conventional maintenance apparatus 10 capping and wiping a surface of an ink ejection nozzle 3 by using a moving force of a carriage 1 is mounted.
The maintenance apparatus 10 is disposed at a maintenance area to clean and close up the surface of the ink ejection nozzle 3 of a printing head 2 using a wiper 22 and a cap 34, respectively, when the printing head 2 mounted in the carriage 1 is in a standby mode or not used for a long time after completing a printing operation of ejecting ink on paper by moving right and left in a printing area by a motor (not shown) driving the printing head 2.
As shown in FIGS. 2 through 3B, the maintenance apparatus 10 comprises a capping member 30 moving from a standby position, as shown in FIG. 3A, opening the surface of the ink ejection nozzle 3 to a capping position, as shown in FIG. 3B, closing up the surface of the ink ejection nozzle 3 by ascending by the moving force of the carriage 1 when the carriage 1 is moved to a maintenance area, a wiping member 20 vertically ascending and descending a wiper 22 wiping the surface of ink ejection nozzle 3 by being rotated right and left by a movement of the capping member 30, and an elastic member 40 elastically returning the capping member 30 from the capping position to the standby position when the carriage 1 is moved to the printing area.
The capping member 30 includes a cap case 31 having a pusher 32 projecting upwardly from one side of an upper surface thereof to be pushed by the carriage 1 and guide projections 38 formed on both side walls thereof to be respectively inserted in first guide slots 15 of a housing 11; and a cap 34 disposed on the upper surface of the cap case 31.
The cap 34 formed of a rubber material is fixed on a top of an axis part 37 enclosed by a spring 33. Accordingly, the cap 34 is pushed upwardly by an elastic force of the spring 33 to close up the surface of the ink ejection nozzle 3 of the printing head 2 during a capping operation.
The wiping member 20 includes a wiper body 21 having a wiper 22 formed of a rubber material and projecting upwardly therefrom and wiper axis parts 23 projecting from both sides thereof to be inserted in wiper axis-receiving slots 14 of the housing 11; and an operating rack 24 disposed below the wiper body 21 and having an operating lever 25 which is moved right and left by the cap case 31 of the capping member 30 to ascend and descend the wiper body 21.
The elastic member 40 is a tension spring having one end fixed to a spring hanging piece 16 formed on a bottom of the housing 11, and the other end fixed to a spring hanging hook 36 formed on a lower part of the cap case 31.
In a maintenance operation, the printing head 2 mounted in the carriage 1 is moved to the maintenance area after completing the printing operation of ejecting ink on paper by moving right and left in the printing area by the motor driving the printing head 2, as shown in FIG. 3A.
When the carriage 1 moves to the maintenance area, the printing head 2 mounted in the carriage 1 passes over the wiper 22 of the wiping member 20. However, at this time, since the wiper 22 is maintained in a descended position, the surface of the ink ejection nozzle 3 of the printing head 2 is not wiped.
After that, when the carriage 1 continuously moves right and is disposed above the cap 34, the carriage 1 pushes a pusher 32 right against a tension force of the tension spring 40 as shown in a dotted line in FIG. 3A. As a result, the cap case 31 is moved right together with the carriage 1 and at the same time ascends by the guide projections 38 slid along the first guide slots 15.
Accordingly, the cap 34 fixed on the upper surface of the cap case 31 is gradually raised together with the cap case 31 and then disposed in the capping position to completely close up the surface of the ink ejection nozzle 3 to prevent ink from being dried off.
Also, at this time, a sliding end 26a of the operation lever 25 is slid from a right end to a left end of a second guide slot 35 and then pulled right by the left end thereof. Accordingly, the operating rack 24 is rotated clockwise until being stopped at a vertical position by a stopping projection (not shown). Consequently, the wiper body 21 having the wiper 22 formed on the upper surface thereof is engaged with a raising portion 24a of the operating rack 24 and thereby disposed in a position (FIG. 3A) by ascending upwardly as much as a vertical height raised by the raising portion 24a. 
Thereafter, when a printing command is generated, the carriage 1 is moved in a direction toward the printing area disposed on a left side of the position shown in FIG. 3B to move away from the cap case 31.
Accordingly, the cap case 31 is lowered since the guide projections 38 are slid left along the first guide slots 15 by a restoring force of the tension spring 40.
At this time, the sliding end 25a of the operation lever 25 is slid from the left end to the right end of the second guide slot 35 and then pushed left by the right end thereof. Accordingly, the operating rack 24 is rotated counterclockwise.
As a result, the wiper body 21 descends after being maintained in an ascending position as much as a width of the raising portion 24a of the operating rack 24.
In a state that the wiper body 21 is maintained in the ascended position, when the carriage 1 continuously moves to make the printing head 2 to pass above the wiper body 21, the surface of the ink ejection nozzle 3 is wiped by the wiper 22 of the wiper body 21 which is maintained in the ascending position.
After the surface of the ink ejection nozzle 3 is wiped, when the operating rack 24 is further rotated counterclockwise by the right end of the second guide slot 35 pushing left the sliding end 25a and thereby the wiper body 21 is engaged with a lowering portion 24b of the operating rack 24, the wiper body 21 is lowered by the lowering portion 24b to be disposed in the position (FIG. 3A) descending as much as a vertical height.
After that, the carriage 1 is moved to the printing area to perform the printing operation by moving right and left the printing head 2.
As described above, the maintenance apparatus 10 has a structure that in order to ascend and descend the cap case 31 by using the moving force of the carriage 1, the guide projections 38 of the cap case 31 are moved along the first guide slots 15 having a given tilt angle with the surface of the ink ejection nozzle 3. Therefore, the smaller the tilt angle of the first guide slots 15 is, the better and the more smoothly the cap case 31 can be moved along the first guide slots 15. In this case, however, a movement distance of the cap case 31 is lengthened as much as the tilt angle of the first guide slots 15 is reduced, thereby resulting in an increase in a size of the maintenance apparatus 10 and the inkjet printer.
Particularly, to reduce a movement distance of the cap case 31, if the first guide slots 15 are tilted at an angle of more than 45xc2x0, it is very difficult for the cap case 31 to smoothly ascend or descend along the first guide slots 15, and a noise is severely generated.
Also, in the conventional maintenance apparatus 10, during the capping operation, the cap 34 obliquely ascends at a horizontal positioned state to be in contact with the surface of the ink ejection nozzle 3, and then closes up the ink injection nozzle 3 by being further pushed.
Accordingly, in the capping operation, a pressure in a seated space between the cap 34 and the printing head 2 is increased in a moment, thereby generating pressured air flowing into capillaries of the ink ejection nozzle 3. As a result, in the printing operation, the ink ejection nozzle 3 of the printing head 2 is not able to eject ink normally, thereby causing a problem of deteriorating printing quality and reliability of the inkjet printer.
Therefore, it is an object of the present invention to provide an improved maintenance apparatus of an inkjet printer which can stably perform a maintenance operation as well as minimize a size thereof.
It is another object to provide an improved maintenance apparatus of an inkjet printer which can increase reliability thereof by preventing an operation error of ink ejection nozzles generated due to a clog of the ink occurring caused by an inflow of pressured air thereinto in a capping operation.
Additional objects and advantages of the invention will be set forth in part in the description which follows and, in part, will be obvious from the description, or may be learned by practice of the invention.
These and other objects of the present invention may be achieved by providing a maintenance apparatus of an inkjet printer including a housing, a capping member disposed in the housing and having at least one cap closing up a surface of an ink ejection nozzle of at least one printing head, a wiping member disposed in the housing and having a wiper wiping the surface of the ink ejection nozzle of the printing head, a transmission disposed on the housing to receive a rotation force from a driving source, a capping member mover changing the rotation force of the transmission into a vertical force and transmitting the vertical force to the capping member, a wiping member mover changing the rotation force of the transmission into a horizontal force and transmitting the vertical force to the wiping member, and wherein a wiping operation of the wiping member wiping the surface of the ink ejection nozzle and a capping operation of the capping member closing up the surface of the ink ejection nozzle are successively performed when the transmission is operated to transmit the rotation force in one of clockwise and counterclockwise directions, and a capping-release operation of the capping member opening the surface of the ink nozzle and the wiping operation of the wiping member are successively performed when the transmission is operated to transmit the rotation force in the other one of the clockwise and counterclockwise directions.
The transmission includes at least one gear member operatively connected to the capping member mover and the wiping member mover to reduce the rotation force received from the driving source and transmit the reduced rotation force to the capping member mover and the wiping member mover. Preferably, the driving source is a separate motor different from a motor driving the printing head.
The capping member mover includes a connecting pin rotatably coupling one end of the capping member to the housing to serve as a hinge of the capping member and a first crank mechanism having a crank gear engaged with the gear member of the transmission, a crank axle coaxially connected to the crank gear, at least one first crank arm having one end connected to the crank axle, and at least one first connecting rod having one end connected to the other end of the first crank arm and the other end connected to the other end of the capping member. Preferably, the connecting pin of the capping member mover is disposed to allow the cap disposed on an upper surface of the capping member to come in contact with the surface of the ink ejection nozzle at a given-initial angle from the surface of the ink injection nozzle and then gradually to close up the surface of the Ink ejection nozzle when the capping member is moved to a capping position to close up the surface of the ink ejection nozzle.
The wiping member mover includes at least one guide groove formed at the housing, at least one slide projection formed on the wiping member horizontally to slide in and along the guide groove, and a second crank mechanism having the crank gear engaged with the gear member of the transmission, the crank axle coaxially connected to the crank gear, at least one second crank arm having one end connected to the crank axle, and at least one second connecting rod having one end connected to the other end of the second crank arm and the other end connected to one end of the wiping member.
The capping member mover and the wiping member mover are disposed to ensure that the capping member and the wiping member are moved in a direction perpendicular to a moving direction of the printing head.
In the maintenance apparatus of the invention, the wiping member includes a used ink-storing part receiving ink spat through the ink ejection nozzle of the printing head during a spitting operation of the printing head.
Also, the maintenance apparatus further includes a stopper stopping the first crank mechanism of the capping member mover to a position having a given capping-maintaining angle beyond a top dead center thereof, to maintain the capping member in the capping position, even though an electrical source of the driving source of the transmission is switched off from the driving source or the capping member is left as is in the capping position for a long time after being arrived at the capping position. Preferably, the stopper includes a projecting part formed in the guide groove of the housing to block movement of the slide projection of the wiping member. Also, preferably, the capping-maintaining angle is set within the range of 2xc2x0-10xc2x0.